Plug for lug straps



ukj' 2 H. E. WILSON 2,337,218

PLUG FOR LUG STRAPS Filed Def. 1 1941 2 Sheets-Sheet 2 .lnvenror.

[2 7 2'sb HerberTEWilsonbYMJQM (JAM I Anys- Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE PLUG FOR LUG STRAPS Application October 1, 1941, Serial No. 413,151

2 Claims.

This invention relates to lug straps for looms, and particularly to the plug with which some types of lug straps are equipped to provid the picker-stick engaging portion.

One of the objects of the invention is to provide a plug for a lug strap which has a working face of resilient material such as rubber. An advantage resulting from this construction is that the impact of the lug strap against the pickerstick will be cushioned, thereby reducing both the noise incident to, and the vibration caused by such impact.

My improved plug for lug straps is formed with a body section made up of layers of fabric adhesively united by vulcanizable material under pressure and suflicient heat to cause vulcanization of such material, and an impact-receiving section of resilient material, suchas rubber or rubberlike material, which is vulcanized to the working side of the body portion.

The body portion of the plug is hard and rigid and provides a proper anchorage for the bolt or rivet by which the plug is securedto the lug strap, but becauseof the resiliency of the impact-receiving section the impact of the plug against the picker-stick will be cushioned.

, In the drawings wherein I have illustrated some selected embodiments of my invention Fig. l is a viewillustrating a preparedsheet of fabric from which the body portion of the plug is made.

Fig. 2 shows this. sheet of fabric rolledup into the form of aroll. Fig. 3 is a. fragmentary. sectional view showing the operation of molding or compressing ,theroll into the shape for the body portion of the plug. Fig. 4 is a similar view showing the cover of the mold removed for the purpose of adding the rubber portion of the plug. Fig. 5 is a fragmentary perspective view illustrating the operation of molding the rubber impact-receiving section to the body of the plug.

Fig. 6 is a section on the line 66, Fig; 5.

Fig. 7 is a fragmentary perspective view showing the article which has been removed from the mold and which is subsequently cut transversely to form individual plugs. j

Fig. 8 shows one of the individual plugs cut from the element shown in Fig. 7. V

Fig. 9 is a perspective view, of a lug strap equipped with my improved plug. V Figs. 10 and 11 are fragmentary views similar to Figs. 3 and 5 but showing a mold designed to form a plug having a different shape from that shown in Fig. 8.

Fig. 12 is a section on the line l2-l2, Fig. 11.

Fig. 13 is a perspective view of the type of plug which is formed in the mold shown in Figs. 10 and 11.

Fig. 14 is a fragmentary perspective view of the presser element employed during vulcanization of the rubber impact-receiving section.

Referring first to Fig. 9, l indicates a lug strap for looms of the type which is provided with a plug 2 in the bight 3 thereof, said plug 2 providing the working face for the lug strap which contacts with, and has impact engagement with the picker-stick of the loom.

As stated above, one of the objects of my invention is to provide a plug which is constructed so that the working face thereof is made of resilient or elastic material such as rubber so that the impact engagement of the plug with the picker-stick will be a cushioned impact.

Fig. 8 shows the plug 2 removed from the lug strap. This plug comprises the body section 5 made up of layers of fabric adhesively united with vulcanizable material under pressure and sufficient heat to cause vulcanization of thevulcanizable material, and an impact-receiving sec tion 6 of rubber, or some other suitable mate-" rial which is resilient or yielding, and which isvulcanized to the body section 5. Both the body section 5 and the impact-receiving section 6 extend the full length and width of the plug, and their end faces as well as their side faces are flush with each otherj The body section 5 of the plug is provided with a transverse opening J to receive the'usual bolt or rivet 8 by which the plug is secured in the lug strap. A body section thus made is hardand rigid-and provides afirm anchorage for such bolt or rivet.

The body section 5 of my improved plug is made by rolling up into the form of a roll, a strip of fabric loaded with somevulcanizable material such, for instance,'as rubber latex, or gutta-percha, and then molding or shaping said roll so as to give it the desired shape for the body section.

The strip of fabric from which the body section is made may have a width corresponding to the dimensions of a single plug or it may have a greater width, in which latter case the roll that is formed from this strip of greater width would be long enough so that several plugs could be cut from it.

In Fig. 1, I have shown at 9 a strip of suitable fabric, such as canvas, which has been loaded with some vulcanizable material IIJ such, for instance, as rubber latex. This strip of fabric 9 is rolled up into a tight roll I I as shown in Fig. 2, and the roll illustrated in Fig. 2 is long enough so that several individual plugs can be made therefrom.

This roll II is then placed in a suitable mold in which it is compressed and vulcanized and also given the desired cross sectional shape for the body section 5 of the plug 2. While any suitable mold may be used for this operation, I have, for illustrative purposes, shown a mold comprising a mold body I2 having a mold cavity I3 and a cover or presse element I4 which is of a size to fit into the open side of the mold cavity I3. The roll II is placed in this mold cavity I3 and the presser member I4 is then put in position and pressure applied thereto, thereby to subject the roll II While the roll II is under pressure in the mold, it is subjected to sufiicient heat to cause vulcanization of the vulcanizable material I9. The layers of fabric are thus not only adhesively united but they are vulcanized together thereby making a solid, hard, unyielding body which has a cross sectional shape determined by the shape of the mold cavity I3 and the face I5 of the presser member I4.

After the roll II has been thus shaped and compressed, the cover I4 is removed and then a layer I6 of rubber or rubber-like material and of generous thickness is laid on the shaped roll II. Another presser element I I is then assembled with the mold body I2 and the shaped roll I I together with the rubber layer I6 is again subjected to pressure as shown in Figs. 5 and 6. At this time, the mold will be heated sufiiciently in some suitable way so as to cause vulcanization of the rubber and at the same time to vulcanize the rubber layer I6 to the shaped'roll I I. This vulcanizing of the rubber layer to the shaped roll is made possible because of the presence in the roll of the vulcanized rubber latex.

The under face of the presser member I1 is shown as scalloped by being provided with the concavely curved sections I8, each section I8 having a length corresponding to that of the plug 2.

The presser member I l is shown as having fins or webs 23 extending from its active face (see Fig. 14) at the intersection of each two adjacent concavely curved sections I9. These webs or fins extend the full width of the member I! and when said presser member is placed in the mold after the rubber layer 16 has been introduced, the pressure to which the member I! is subjected forces the fins 23 through the rubber layer, thereby dividin the latter into separate sections, one for each of the concavely curved sections I8 f the presser member. When, therefore, the rubber layer It is vulcanized it has been divided into these separate sections by the fins 23.

After the vulcanizing operation has been completed, the mold is opened and the article 2! which is removed from the mold and has been formed therein, has then the shape and structure shown in Fig. '7. This article comprises a body portion of fabric having the rounded side I9 and the rubber portion I6 of generous thickness which is vulcanized to one side of the body portion 5. This rubber portion is composed of the separate convexly curved sections '39 which to considerable pressure.

were formed by the scalloped shape I8 of the presser element [1 and which are separated from each other by the spaces 24 formed by the fins 23.

The molded element 2| shown in Fig. '7 may then be cut transversely in the planes of the spaces 24 or along the dotted lines 22 in Fig. '7, thereby providing a plurality of plugs 2 such as is shown in Fig. 8, each plug presenting the body section 5 of fabric and the impact-receiving section 6 of rubbe which is of generou thickness and which is vulcanized to one side of the body section 5. The two sections 5 and B extend the full length of the plug and their end faces are flush with each other; said two sections also both extend the full width of the plug so that their side faces are also flush with each other.

The advantage of forming the element 2I with the slots or dividing spaces 24 in the vulcanized rubber is that the operation of cutting the individual plugs from the element 2| involves only that of cutting through the body portion and does not involve the operation of cutting through the vulcanized rubber section.

After the individual plugs have been severed from the element 2| the hole I will be formed in the body section of each plug. When a plug such as shown in Fig. 8 is assembled with the lug strap, the rounded side I9 thereof fits the curve at the bight 3 of the lug strap and the convex face 4 of the rubber impact-receiving section provides the face which contacts with the pickerstick.

In Figs. 10 and 11 and 12, I have shown a type of mold which is designed to form a plug 20 such as shown in Fig. 13 in which the rubber section Ba is provided with a concave face 4a instead of the convex face 4 shown in Figs. 8 and 9. In making a plug of the type shown in Fig. 13, the roll II of fabric which has been loaded with some vulcanizable material is placed in the mold member l 2 and is subjected to pressure by means of a pressure member I la which has a convex face I511. During the application of pressure to the roll, the mold will be heated sumciently to cause vulcanization of the vulcanizable material with which the roll is loaded.

After the roll II has thus been shaped as shown in Fig. 10 and has been subjected to the vulcanizing operation, the presser member Ma is re-' moved and a layer of rubber Iiia is applied to the shaped roll. Another presser element Mbsimilar to the presser element I ia but having the fins 23b extending from its active face, is then assembled with the mold member I 2, and the rubber layer and shaped roll is again subjected to pressure. When pressure is applied to the presser member I417, said fins 23b will be forced through the rubbe layer, thereby dividing the latter into separate sections. These fins are spaced apart a distance equal to the length of a completed plug. While the pressur is applied to roll I I and rubber layer Ita through the presser member I to, the mold will be again subjected to sufiicient heat to effect vulcanization of the rubher and to vulcanize the rubber layer 46 to the fabric body II. After the vulcanizing operation has been completed, then the mold is opened and the molded article removed therefrom. If such article ha a length equal to several plugs 29, then such article may be cut transversely along the lines of division between the sections of the rubber facing which have been formed by the fins 23b, thereby forming a plurality of plugs such as shown in Fig. 13. The convex shape Ilia of the presser member Ma serves to give the working face of each plug 20 the concave shape shown at 4a at Fig. 13.

In the illustrated embodiments of the invention, the mold is of a length to provide a molded article from which several plugs can be cut. It would, however, be within my invention to use a strip of fabric 9 having the correct width to produce a single plug, only in such case, the mold element employed would have a length equivalent to that of the individual plug.

I claim:

1. A plug for a lug strap comprising a body section and an impact-receiving section, each extending from one end to the other of the plug, said body section being composed of a roll of fabric loaded with vulcanizable material and extending from one end to the other of the plug, said roll being compressed transversely to form a compact body portion having a cross-sectional shape to fit within the bight of a U-shaped lug strap; the individual layers of the roll being vulcanized together. and said impact-receiving section being made of rubber and being vulcanized to the side of the body section opposite the convexly curved side thereof, said impact-receiving section being relatively thick and extending the full length and width of the body portion.

2, A plug for a lug strap presenting two parallel side faces, a rounded back face and a front impact-receiving face, said plug being divided transversely from end to end and from one parallel side face to the other to present a body section forming the rear portion of the plug and a relatively thick impact-receiving section forming the front of the plug, the body section being formed of a roll of fabric extending from one end to the other of the plug and loaded with vulcanizable material, said roll being compacted transversely and the turns of the roll being vulcanized together, said impact-receiving section being relatively thick and being vulcanized to the body section, said impact-receiving section extending the full length of the plug and from one parallel side face thereof to the other.

HERBERT E. WILSON. 

